Smoothing device



1! from the mains.

Patented Oct. 23, 1934 PArs r OFFICE SMOOTHING DEVICE Johan Willem Alexander and Ekko Costerhuis, Eindhoven, Netherlands, assignors to Radio ware Corporation of America, a corporation of Dela- Application February 25, 1930, Serial No. 431,238

I In Germany April 5, 1929 1 Claim.

1 l0 pressing the alternating current components still in existence after the rectification of the alternating currents.

These smoothing devices are generally notsufiicient to suppress the disturbances emanating It has been found that a considerable improvement can be obtained in this respect by the use of an additional smoothing device arranged before the usual battery eliminator and consisting 3 of two choke coils and two condensers. In each of the two leads is connected a choke coil and between the ends, of the choke coilswhich are turned towards the mains-fed apparatus are connected in series two condensers whose point of connection is earthed.

Instead of being directly connected to the mains, the smoothing device should conveniently be connected thereto through the intermediary of a transformer which is preferably mounted 0 together with a smoothing device in one case.

The use of a transformer at this point offers the additional advantage that all the batteryeliminators can be constructed for the same tension so that only by adding the right trans- "3'5 former any apparatus can be adapted to the voltage of the mains.

The transformer preferably comprises a core which is nearly saturated at normal values of the current so that the secondary voltage is independent of voltage fluctuations of the mains.

The invention, will be more clearly understood by referring to the accompanying drawing which represents by way of example a circuit arrangement and a mode ofrealization.

the smoothing device in accordance with the I present invention. 7

, Figure 2 is a lateral elevation of a smoothing device mounted together with the transformer in a single case.

are each connected to aterminal of the second- Figure 1 represents a circuit-arrangement of (Cl. 178-44) l ary coil 5. The other ends of the choke coil are connected to leads l1 and 12 and are connected to one another by condensers 8 and 9 whose connecting point 10 is connected to earth, the usual mains-fed apparatus being connected to the leads 59 11 and 12.

Referring to Figure 2, 7 denotes a choke coil which is preferably wound in various parts. The separate parts of the coil which are denoted by 13, are located on a carrier 14 which is secured to the walls 16 and 17 by means of screws 15. One of the ends of the choke coil is connected to the terminal 18 of a condenser 19 whose other terminal 20 is connected at 21 with a wall 22 from Figure 3. Moreover, the terminal 18 is connected to the terminal 11 destined for the connection of the usual high-tension supply unit. The ends 23 and 24 of the secondary winding are each connected to one of the choke coils; 6 and 7 by means of the connecting leads 25 and 26. The connection of the primary winding is effected by a flexible cord 27. 28 denotes a terminal which allows of connecting the wall 22 to earth. The base 29 of the apparatus consists of metal. The dotted line 30 indicates a metal cover which can be placed on the whole apparatus. It has such dimensions that the upper edges of the walls 16, 22 and 17 come in contact with the cover so that, so to say, two compartments 185 apparatus so as to form a unit.

We claim In a voltage regulating device connected between the power mains and the power conditioning circuit of radio apparatus, a metallic enclosure member having three compartments, a re- :placeable transformer in one of said compart- 1 00 ments,said transformer being adapted to become substantially saturated during normal operation thereof, a condenser and a choke coil in another of said compartments and a second condenser and a second choke coil in the third compart-,;1 05 ment, means for connecting the primary of said transformer to the power mains, means for connecting a terminal of one of said choke coils to a terminal of the secondary of said transformer and a terminal of the other of said choke coils :llq

said choke coils, means for connecting the free terminal of the other condenser to the free terminal of the other of said choke coils, and means for connecting said last-named terminals of said two choke coils to the power conditioning circuit. JOHAN WILLEM ALEXANDER.

EKKO OOSTERHUIS. 

